When trying to perform bulk task operation(start/complete) then it fails with below exception:

2020-07-28 15:01:35,221 WARN [org.hibernate.engine.jdbc.spi.SqlExceptionHelper] (default task-1282) SQL Error: -803, SQLState: 23505 2020-07-28 15:01:35,221 ERROR [org.hibernate.engine.jdbc.spi.SqlExceptionHelper] (default task-1282) DB2 SQL Error: SQLCODE=-803, SQLSTATE=23505, SQLERRMC=1;$SCHEMA_NAME.ORGANIZATIONALENTITY, DRIVER=4.19.66 2020-07-28 15:01:35,222 WARN [org.jbpm.services.task.persistence.TaskTransactionInterceptor] (default task-1282) Could not commit session: javax.persistence.PersistenceException: org.hibernate.exception.ConstraintViolationException: 
could not execute statement

This issue occurs when task operation is performed by new users in parallel by multiple threads. This issue can be avoided by these two options:

Update the database with this new user entry before the bulk task operation
Complete a single task operation request first and then send the rest of the requests in parallel.

[NOTE ENG](Not related to sync tables)

I give some thought how to fix the issure related to Duplicated entity (race condition problem regarding saving org entities in the database.

There is a way to serialize this with JMS would be to add a special queue to save this org entities outside the current transaction and before starting the task (we can a hidden action node prior the human task in charge of this, causing an async execution of the human task.

[Start]> [Task] > [End]

Would be transformed to:

[Start]> [user save action node; hidden node] > [task; async=true] > [end]

1) The user save action would send the org entities to a queue with a correlation key

2) the MDB would retrieve that info a save it to the databasse

3) it will be send back with a correlation key

4) continue workflow.